Metal working



Patented Feb. 22, 1927.

UNITED STATES PATENT OFFICE.

must wonxmc.

Application fled Kay 28, 1921. Serial No. 478,477.

The present invention relates to the art of metal working and consists essentially in working the metal by subjecting the same to a high compression while it is under a high tension. More particularl the working consists of reducing the thic ess or seetional area and of elongating the len h of the piece by a combined pulling an com-- pressing means.=

I have found that the pulling of a iece of steel at a high tension, for examp e at near its elastic limit, while compressing it between rolls at about its crushing strength there is produced very much more fluldlty in the metal and at the same time much less hardening eifects on the steel due to rolling. This permits the rolling to be carried on to a very much reater extent than where onl compression etween the rolls is employe as in present practice.

In the old method of cold rolling of low carbon steel, by simply assing it between the rolls, an elongation o from to 50% is about all that the steel will withstand 25 without reannealing. Somewhat greater elongations can be made, especially if the steel is a low carbon steel and if small diameters of rolls are used. The effect of the lat ter is to produce an excessive elongation for each passage of the metal through the rolls.

According to my new method of combined pulling and compressing, very much greater elongations are obtainable in a given carbon and anneal of the steel, without the necessity of reannealing. Thus as demonstrated by me when a. high tension is in one direction and a large compression is at substantially right angles thereto there is produced a greater resultant force within the steel which produces a very much greater fluidit of the metal. Under such conditions I ave obtained elongations of from 100096 to 1200% and the material does not appear to be in any greater need of reannealing than did steels which were elongated from 25% to or possibly 100% by the old non-- pulling method.

In the accompanying drawing, Fig. 1, I

50 have illustrated my invention diagrammatically representing the pulling of the piece after passing the rolls. Figure 2'represents ,a tension in the piece produced by a pull at each end. Figure 3 shows the rolling of a hoop or steel belt. Figure 4 shows a sim le diagram of two equal forces at right ang es and their resultant force. In these diagrams, 10 designates a piece of metal pass ing between rolls 11 and 12 and having its end or ends engaged by a gripping and tensionmg device 13. As soon as the forward end of the piece 10 is passed beyond the rolls 11 and 12, the device 13 is attached to it. The necessary tension is then given to the steel by pulling on the dev ice 13, as indicated by the ad acent arrow 14. The amount of pull, as before noted, should be very great approximating for example, the elastic limit of the metal. A heavy compression 1s applied to the metal of the rolls 11 and 12. These rolls are driven as usual and are pressed toward each other, as indicated by the opposed arrows 15, by any suitable com pressing means, such as a screwdown, examples of which will be found in my prior United States Patents No. 1,211,029, granted April 3rd, 1917, and No. 1,233,647, granted July 17th, 1917. The amount of compres- SlOn, as before noted is in the nei hborhood of the crushing strength or elastic limit of the metal of the strip 10, or a slightly greater pressure may be used.

Under certain conditions, we may apply the high tensional force to the piece on the entering side of the mill and in other cases to only the out oing side of the mill. When the pull is app ied to only the outgoing end, there is a tendency for the material to accumulate in front of the rolls, as at 16, as a sort of bulge or double wave. But when a pull is exerted on the ingoing end as in Figures 2 or 3, this wave does not appear, as at 17. The disappearance of this wave is of assistance in accomplishing great elon tions. In cold rolling, 16 and 17 are usufily not apparent to the eye, but the tendency exists, nevertheless.

The figures represent the forces of tension and compression as being. approximately equal. In actual lpractice they are not required to be equa There is no well defined stress in the compression or tension applied at which the greater fluidity begins or ends. If the material is of muchvalue as is a steel belt, I recommend keeping the pull safe] below the elastic limit and increasin the compression to such a point as to pro uce the desired fluidity 1n the reduc tion. If rapid reduction or great reduction is desired, a pull can be exerte closer to the elastic limit or even exceeding it.

In the old method, the flow occurs under the sole impulse of the com ressive force of the rolls while in my met od there are two more or less equal forces actin simultaneously at ri ht angles to each other, the resultant of w 'ich forces is roughly 40% greater than either of the components, when they are equal. \Vhen they are une ual, the resultant is less than 40% greater t an the maximum of the two forces.

The metal 10 may be rolled when either hot or cold and may be presented in any shape, such as a belt, band, sheet, strip, bar, tube, wire, rod or the like. It, of course, maly be any malleable or ductile metal.

n the diagram of forces of Fig. 4, the horizontal line a 6 represents the tensional force pulling in the direction of the arrow 14, the line a a, re resents the compressing force acting in the irection of the arrow 15, and the line a 5 represents the resultant force. As here shown. the two component forces are equal and the resultant force in this case is, roughly, 40% greater. These relative values are here shown by the numerals 1, 1 and 1.4 upon the diagram. Obviously with slight e anges in the direction or ma itude of the components, chan es would li e produced in the resultant. T is diagram does not contemplate the secondary forces which are acting in my rocess, Although I have used the word uidity in several instances throughout this description, it may be that such words as ductility or plasticity would more correct] define the action or condition of the meta This might be further explained by reference to the art of malleation wherein metals are worked down to extreme thinness by a hammer or by means of rolls. In that aspect of the present invention, the force exerted on the metal blank by the pressure of the rolls is a malleating force which is superior to the resistance of the metal, causing the latter to flow and spread and thereby be reduced in thickness. Simultaneously, in fact exactly coincident therewith, another force is applied to the metal blank at the time the malleating pressure is imposed thereon, namely, an elongating forcewhich is exerted preferably in a direction at right angles to the line of force of the rolls. resultant of these two forces within the body of the metal is greater than either of said forces singly and is also greater than the elastic limit of the metal with the. result of obtaining the deformation of the metal in the manner contcm lated. This im rtlm phase of the inventlon distinguishes om other materials t What I claim as new and desire to se- .elastic limit, the two forces being The prior suggested practices wherein a mere tension is maintained onthe metal while it is bein rolled, simply to keep it in form. It should borne inanindthat the present invention is also aglplicableto the working of an metal,

cure by Letters Patent of the United States, 1s-

1. The method of working a ferrous metal piece which includes the operations of pressing the piece between rolls a plying a force ap roac ing the elastic linnt of the metal, an simultaneously drawin out the advancing portion of the piece yond the rolls with a tensional force approaching the clastic limit of the metal.

2. The method of working ferrous metal which includes the operations of pulling the metal longitudinally throughout its whole length at about its elastic limit and at the same time compressing the same transversely throughout its whole thickness at abontrits a 1e simultaneously and the com ressive orce being applied progressively t roughout the length of the meta 3. The method of working metal which includes the combined operations of pulling an endless piece of metal throughout its whole length and com ressing the metal progressively, each force icing applied at about the elastic limit of the metal and both forces being effective at a common point.

4. The method of greatly extending the length and greatly reducing the thickness of a piece of ferrous metal by subjecting the same, one transverse portion after another in succession, simultaneously to a compressive stress and a tensile stress, each stress being at about the elastic limit of the metal and each acting upon every point in the successive cross sections worked upon, whereby all parts of the metal piece, except p0sslbly the ends, are subject at one time or another to the resultant of both said stresses.

5. The method of greatly extending the length and greatly reducing the sectional area of a piece of ferrous metal, by subjecting the transverse portion of the metal simultaneously to a compressive stress between reducing rolls and to the tensile stress applied by a pulling device over which said piece has been looped, each stress being at about the ela'stic limit of the metal and being applied progressively, simultaneously each with the other, along the length of the piece.

6. The method of elongating a piece of metal to more than five times its original len h withoutreannealing the piece, which met 0d consists in simultaneously applying to the piece successively from point to point along its length tensional and compressional forces each in the neighborhood of the elastic limit of the metal directed at an angle to each other so that the resultant force within pressive stress exerted by the rolls and the the metal has a ater value than either of tensile stress both approaching the respective said component orees. elastic limits of the metal. 10

7. The method of progresively rolling an In testimony whereof, I hereunto sub- 5 endless strip by assing it round and round scribe my name this 25th day of May A. D.

through a pass etween rolls and a plying 1921. tension to the length of the strip, t e com- WILLIAM C. CORYELL.

each other so that the resultant force within pressive stress exerted by the rolls and the the metal has a eater value than either of tensile stress both approaching the respective said component orces. elastic limits of the metal. In

7. The method of progressively rolling an In testimony whereof, I hereunto sub- 5 endless strip by assing it round and round scribe my name this 25th day of May A. D.

throu h a ass etween rolls and a plying 1921. tensioi to the length of the strip, t e com- WILLIAM C. CORYELL.

DISCLAIM ER 1,618,515.-W'illiam O. Ooryell, Youngstown, Ohio. METAL WORKING. Patent dated February 22, 1927. Disclaimer filed December 11, 1934, by the assignees, United Engineering (f: Foundry Company and American Sheet (2 Tin-Plate Company. Hereby dischim from said specification that part thereof appearing in lines 17 and 18 of age 2, reading as follows: when eit er hot or.

And your petitioners further hereby disclaim from said specification that part thereof appearing in lines 19, 20 and 21 of page 2, reading as follows: "bar, tube, wire, rod or the like. It, of course, may be any malleable or ductile metal. d your petitioners further hereb disclaim from said specification that part thereof appearing in lines 68, 69, 70, an 71 of page 2, reading as follows:

"It should be borne in mind that the present invention 18 also applicable to the working of other materials than metal.

And your petitioners further hereby disclaim from the scope of each of claims 1 to 6 inclusive, all material except ferrous metal belts, bands, sheets and stri s, and all ferrous metal belts, bands; sheets and strips not having a width materi y greater than that of flat wire.

[Oficial Gazette January 1, 1935.]

DISCLAIMER l,618,515.lVilliam C. C'oryell, Youngstown, Ohio. METAL WORKING. Patent dated February 22, 1927. Disclaimer filed December 11, 1934, by the assignees, United Engineering cf: Foundry Company and American Sheet (f; Tin Plate Compan Hereby disclaim from said specification that part thereof appearing in lines 17 and 18 of age 2, reading as follows: when either hot or".

And your petitioners further hereby disclaim from said specification that part thereof appearing in lines 19, 20 and 21 of page 2, reading as follows: "bar tube, wire, rod or the like. It, of course, may be any malleable or ductile metal. And your petitioners further hereb disclaim from said specification that part thereof appearing in lines 68, 69, 70, an 71 of page 2, reading as follows:

It should be borne in mind that the present invention is also applicable to the working of other materials than metal.

d your petitioners further hereby disclaim from the scope of each of claims 1 to 6 inclusive, all material except ferrous metal belts, bands, sheets and stri s, and all ferrous metal belts, bandsysheets and strips not having a width materially greater than that of flat wire.

[Oficial Gazette January I, 1986.] 

